Hollow mill.



UNITED STATES L Patented July 14:, 1903.

PATENT, UFFICE.

HOLLOW MILL.-

SPECIFICATION forming part of Letters Patent of 733,870, dated July 14,1903. Application filed September 12, 1902. Serial at 123,054. (Nomodel.)

To ctZZ whom it may concern:

Be it known that I, WALTER B.-PEARsoN,=

a citizen of the United States, and a resident; of Chicago, in thecounty of Cook and State f of Illinois,'have invented an Improved Hol-Elow Mill, of which the followingis a specification. 1

This invention relates to hollow mills.

Primary objects of the invention are to provide improved and simplifiedmeans for adjusting and supporting the cutters and for securing thecuttersin the cutter head or body.

A hollow mill of my invention consists of the various features,combinations of featu res, and details of construction hereinafterdescribed and claimed.

In the accompanying drawings a hollow mill of my invention is fullyillustrated.

Figure l is-a side view-of a hollow'mill of my invention. Fig. 2 is afront view thereof. Fig. 3 is a partial sectional view on the line 3 ofFig. 2; and Figs. 4 and 5 are side andfront views, respectively, ofa-hollow mill of my invention with the outer section of the head or bodythereof removed.

The hollow mill shown in the drawings is of the type designed for use onscrew-machines, and consists of a head (indicated as a whole, by l) anda shank 2, adapted to be secured in' the turret-head of thescrew-machine. The cutters 3 are preferably rectangular in crosssectionand are secured in slots 4, formed in the head or body 1 of the tool. Asshown, the cutters 3 are loosely fitted to the slots 4 and are securedtherein by means of wedges 5,'i'n-- sorted between said tools and theouter sides of said slots 4. As'shown, the Wedges 5 are tightened inorder to clamp the cutters in position by means of screwed, threadedinto the head or ,body of the tool, collars 7 on which extend inwardlybeyond the outer edges of said wedges, so as to draw said wedges intotheir seats when said screws are tightened. As preferably constructedthe collars 7 are fitted to counterbores Sin the body of the tool. Inthis manner-the side thrust on the screws 6, due to tightening thewedges 5 and which would be very liable to break said screws if theywere unsupported against such side thrust, is transmitted to andsustained by the rigid tool-body. The wedges 5 being set on anglesrelatively to the screws 6, it is obvious shoulders 9. and the recessedshoulders 9 of proper depth that the recesses in the faces of saidwedges corresponding to the counterbores 8 will have to be sufficientlylong to permit of necessary movement of the faces of said wedgesrelatively to-saidscrews. As shown, they extend entirely across saidwedges, forming recessed By making the counterbores 8 the heads ofthe-screws 6 may be made to pro ject only a-desired distance beyond theface of the tool-bod y. As shown, also the sides and bottoms of theslots 4 are formed at an an- .gle to the axis of thehead or body of theout ter, thus making provision foradjusting said ciitters' toward andfrom the axis of the tool and alsdproviding the desired rake to thecutters. As shown, the cutters have a lefthand rake. As shown,thebottoms and sides of said slots both extend at an angle of about tendegrees to the axis of the head or body of the tool.Thisangulardivergence,'however,may be changed to meet varyingrequirements or as desired. The outer sides of the slots etpreferablyextend parallel with the axis of the tool, the desired wedging actionbeing obtained by forming the bottoms of said slots on an incline.Preferably, also, the outer sides of said slots are circular andconcentric with the axis of the tool.

For convenience of construction the head or body of the tool consists ofan inner section 10, formed integral with the shank 2, and an outershell 11, secured in fixed adj ust- 'ment thereon, the outer surface ofthe inner section 10 being turned straight and the inner surface of theshell 11 being bored to fit the outer surface of the section 10, beingpreferably-fitted thereto-verytight, so that whent'forced onto the"section 10 the frictional engagement thereof will secure them in fixedadjustment. The described construction greatly facilitates the formationof the slots 4, said slots being cut in said section 10 beforethe.shell11 is secured thereon, the outer sides of said slots being open as theyare formed in the section 10 and being closed by the shell 11. Thisconstruction likewise facilitates making the wedges 5 and fitting themto the slots 4, the flat sides of said wedges being first formed to fitthe flat sides of said slots, after which their outer surfaces are.

turned off on the same radius. as the surface of the section 10 of thehead or body of the tool and of proper thickness.

Formed on the shell 11 is a flange 12, which projects inwardly beyondthe edge of the section 10 and is provided with a shoulder 13, whichbears against said section 10. Said flange will thus operate to supportsaid shell 11 in position against the pull of the screws 0.

The cutters 3 are adapted to be adjusted inwardly toward the axis of thetool by means of a nut 14, threaded to the shank of the tool, againstwhich the rear ends of said cutters abut. With this construction it isobvious that all of the cutters may be adjusted inwardly simultaneouslyand equally.

The tool is provided with an axial bore 15, which extends rearwardlyfrom its front face and is adapted to receive the milled end of thearticle on which the tool is operating Preferably,also,said borecommunicates with a transverse hole or opening 16, formed in the shank 2thereof, thus making provision for the escape of chips formed by thecutters.

I claiml. A hollow mill consistin of a body por-' tion provided withslots, cutters fitted to said slots, wedges inserted between saidcutters and a side of said slots and independent means to force each ofsaid wedges into its slot, substantially as described.

2. A hollow mill consisting of a body portion provided with slots,cutters fitted to said slots, wedges inserted between said cutters and aside of said slots, independent means to force each of said wedges intoits slot and an adjusting-nut against which the rear ends of saidcutters abut, substantially as described.

3. A hollow mill consisting of a body-portion comprising an innersection provided with slots and an outer shell secured in fixedadjustment thereon, cutters fitted to said slots, wedges insertedbetween said cutters and said outer shell and independent means to forceeach of said wedges intoits slot, sub- I stantially as described.

4. A hollow mill consisting ofa body portion provided with slots,cutters fittedtosaid slots, wedges inserted between said cutters and aside of said slots, screws threaded into the body portion of said hollowmill and'collars thereon which extend over the front ends of said wedgeswhereby said wedges may be forced into said slots, substantially asdetion comprisingan inner section provided with slots and an outer shellsecured in fixed adjustment thereon, being provided with aninwardly-projecting shoulder which bears against the rear side of saidinner section, cutters fitted to said slots, wedges inserted betweensaid cutters and said outer shell, screws threaded into said outer shelland col- .lars thereon which extend over the front ends of said wedgeswhereby said wedges may be forced into said slots, substantially asdescribed.

7. A hollow mill consisting of a body portion comprising an innersection provided with slots and an outer shell secured in fixedadjustment thereon, cutters fitted to said slots, wedges insertedbetween said cutters and said outer shell, independent means to forceeach of said wedges into its slot and an adjusting-nut against which therear ends of said cutters abut, substantially as described.

8. A hollow mill consisting of a body portioncomprising a cylindricalinner section provided with slots and an outer shell secured in fixedadjustment thereon, said outer shell being provided with a shoulderagainst which the rear side of said inner section bears, outters fittedto said slots, wedges inserted between said cutters and said outershell,

screws threaded to said outer shell, collars on said screws whichproject over the front ends of said wedges whereby said wedges may beforced into said slots and an adjust- ..ing-nut against which the rearends of said cutters abut, substantial1y as described.

9. A hollow mill consisting of a body portion provided with slots, thebottoms and lateral sides of which are formed at angles to the axis ofthe body of said tool, cutters fitted to said slots, wedges insertedbetween said cutters and the sides of said slots and independent meansto force each of said Wedges into its slot, substantially as described.

10. A hollow mill consisting of a body portion comprising an innersection provided with slots, the bottoms and lateral sides of which areformed at angles to the axis thereof and an outer shell secured in fixedadjust- -ment thereon, cutters fitted to said slots,

wedges inserted between said cutters and said outer shell, independentmeans to force eachof said wedges into its slot and an adjusting-nutagainst which the rear ends of said cutters abut, substantially asdescribed.

11. A hollow mill consisting of a body por- .tion comprising an innersection provided with slots, the bottoms and lateral sides of whichareformed at angles to the axis thereof and an outer shell secured infixed adjustment thereon, said outer shell being provided with ashoulder which bears against the rear side of said inner section,cutters fitted to said slots, wedges inserted between said outters andsaid outer shell, screws threaded into said outer shell, flanges thereonwhich extend overthe front ends of said wedges and an adjusting-nutagainst which the rear ends of said cutters abut, substantially asdescribed.

12. A hollow mill consisting of a body portion provided with slots,cutters fitted to said slots, wedges inserted between said cutters andthe sides of said slots, screws threaded into said tool-body and flangesthereon which extend over the front ends of said wedges,

said tool-body being provided with counterbores to which saidfiangesare'fitted, substantially as described. A

13. A hollow mill consisting of a body p0l-' tion provided with slotsthe bottoms and lateral sides of which are formed at angles to the axisof the body of said tool, cutters fitted to said slots, wedges insertedbetween ence of two subscribing witnesses, this 19th day of August, A.D. 1902.

WALTER B. PEARSON. Witnesses:

M. S. SOMERVILLE, ARTHUR W. UNDERWOOD.

